mac80211: fix tim_lock locking

The ieee80211_beacon_add_tim() function might be called
by drivers with BHs enabled, which causes a potential
deadlock if TX happens at the same time and attempts to
lock the tim_lock as well. Use spin_lock_bh to fix it.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 5b9602b62405..5800c7a0d075 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -2360,9 +2360,9 @@ static int ieee80211_beacon_add_tim(struct ieee80211_sub_if_data *sdata,
         if (local->tim_in_locked_section) {
                 __ieee80211_beacon_add_tim(sdata, ps, skb);
         } else {
-                spin_lock(&local->tim_lock);
+                spin_lock_bh(&local->tim_lock);
                 __ieee80211_beacon_add_tim(sdata, ps, skb);
-                spin_unlock(&local->tim_lock);
+                spin_unlock_bh(&local->tim_lock);
         }
 
         return 0;